Control device for changing the range of starting point and swing amplitude of a needle in a zigzag sewing machine



Jan. 10, 1967 SHINICHI KAWAGUCHI 3,295,937

CONTROL DEVICE FOR CHANGING THE RANGE OF STARTING POINT AND SWINGAMPLITUDE OF A NEEDLE IN A ZIGZAG SEWING MACHINE Filed July 21. 1965 2Sheets-Sheet l Y INVENTOR.

Jan. 10, 1967 SHINICHI KAWAGUCHI 3, 96,98

CONTROL DEVICE FOR CHANGING THE RANGE OF STARTING POINT AND SWINGAMPLITUDE OF A NEEDLE IN A ZIGZAG SEWING MACHINE Filed July 21, 1965 2Sheets-Sheet 2 Eve INVENTOR. 5///A//c/// M/t AGUCH/ AT Q/ZA/EKS UnitedStates Patent 3,226,987 CONTROL DEVIQE FUR QHANGING THE RANGE 0FSTARTING lPOlN'll AND SWING AMPLTTUDE OF A NEEDLE IN A ZTGZAG SEWINGMACHTNE Shiniehi Kawaguchi, Tokyo, Japan, assignoito lticcar SewingMachine Co., Ltd, Tokyo, Japan, a corporation of Japan Fiied July 21,W65, Ser. No. 473,666 Claims. (Cl. 112ll58) This is acontinuation-in-part of a copending application Serial No. 264,580 filedMarch 12, 1963, now abandoned, and entitled Control Device for Changingthe Range of Starting loint and Swing Amplitude of Needle in a ZigzagSewing Machine.

This invention relates to a novel control device for changing the rangeof needle movement or swing amplitude in a zigzag sewing machine. Morespecifically, the invention lies in the provision of a novel swingcontrol mechanism in a particular arrangement between a zigzaggenerating mechanism and the swingable needle of a zigzag sewingmachine. The present invention permits optional changing of stitch widthand it additionally permits external adjustment (from a point outsidethe machine), of the needle location when it is at a position of maximumswing amplitude. The particular arrangement of the present invention isparticularly useful in connection with the darning of button holes andwith embroidery stitching utilizing a plurality of needles.

Usually, when darning button holes on a zigzag sewing machine, anyadjustment of stitch width along either side of the button holenecessarily brings about a corresponding change in the actual width ofthe button hole, i.e., the distance between the two parallel rows ofzigzag stitches on either side of the button hole. In order to preventsthis, prior machines required very complicated and troublesomemanipulation of their various internal cams and connections.Furthermore, many machines did not even permit of variation in stitchwidth for a given button hole pattern, so that an entirely new buttonhole pattern had to be substituted.

Also, in the case of embroidery stitching, wherein various coloredthreads are sewn with a plurality of needles, such as two needles, threeneedles, etc., it has previously been necessary to change the entire camarrangement within the machine in order properly to control the relativemovements of the needles with respect to each other during the sewingoperation. Thus in known machines, it is not possible to switch from oneto a plurality of needles without completely rearranging the cam set-upwithin the machine.

It is an object of the present invention to provide a zigzag controlarrangement for controlling the width of zigzag needle movement and toshift the position of the needle at its point of maximum swing so as toeliminate all of the above described difiiculties. According to thepresent invention this is accomplished by the provision of anintermediate mechanism arranged between a zigzag generating mechanismand the needle itself; such mechanism being operable to provideadjustment of the amplitude of movement actually communicated to theneedle from the zigzag producing mechanism.

For a more complete understanding of the nature and scope of the presentinvention, reference may be had to the following detailed descriptionwhich may be read in connection with the accompanying drawings,illustrating by way of example a preferred embodiment of the invention.In the drawings:

FIG. 1 is a side elevational view of a sewing machine provided with thenovel swing amplitude control arrangement of the present invention;

FIGS. 2, 3 and 4 are enlarged fragmentary views illus- 3,296,987Patented Jan. lb, 196'? trating needle arrangements and their relativepositions as adjusted by the mechanism of the present invention;

FIG. 5 is an enlarged perspective view of the internal mechanism of thesewing machine of FIG. 1, and

FIG. 6 is a fragmentary sectional view taken along line 6-6 of FIG. 5.

The sewing machine of FIG. 1 is designated by the numeral it). Thismachine comprises a housing 12 having a vertical portion 14, which risesupwardly from a base plate 16, and a horizontally extending arm 18 whichextends cantilever fashion from the top of the vertical portion lid overthe base plate 16. A needle bar 20 extends downwardly from the outer endof the horizontally extending arm 18 and has attached thereto, by meansof an attachment collar 22, one or more needles 24 which reciprocate upand down with the needle bar 20 to penetrate through an opening 26 inthe base plate 16.

There is provided an electric drive motor 28 which turns a pulley 3iabout which is looped a drive belt 32. The drive belt 32 extendsupwardly through the vertical portion 14 of the housing 12 and loopsover an input pulley 34 located within the housing. The input pulley 34is rotatably connected to the main shaft 36 which extends along theinside of the horizontal extending arm 18. Thus the drive motor 28operates to rotate the main shaft continuously.

Referring now to FIG. 5 it will be seen that the needle bar 20 moves upand down in upper and lower needle bar bearings 38 and 40 which areattached to a bar support 42. The needle bar support is pivotallyattached at its upper end 44 to the housing 12 so that it may swing backand forth along the path identified by the letter S in the drawings.

In order to reciprocate the needle bar 20 in its path of verticalmovement there is provided on the end of the main shaft 36, a crank 46to which is pivotally connected a connecting rod 48. The other end ofthe rod 48 is pivotally connected as at 50 to the needle bar 20 so thatas the main shaft 36 rotates, the needle bar 20 will move up and downonce for every rotation of the shaft.

There is additionally provided on the main shaft 36 a zigzag worm 52which engages a zigzag worm wheel 54 mounted to rotate within thehousing 12 about a vertical axle 56. A lobe cam 58 is connected to theupper end of the axle 56 and turns along with the zigzag worm wheel 54.The worm and worm wheel produce a 2:1 speed reduction so that the lobecam 58 will rotate once for each two rotations of the main shaft 36. Thelobe cam 58 is of eccentric configuration with respect to its axis ofrotation so that during rotation its periphery will generate a periodicdisplacement along any fixed radial line extending from its axis. Asshown in FIG. 6, the cam 58 fits closely within a rocking box 60 ofchannel-like configuration. The oscillatory motion produced by the camis thus imparted to the rocking box 60. The rocking box itself ispivotally connected as at 62 to the side of the housing 12. Thus, thelobe cam 58 causes the rocking box to swing back and forth about itspivot point 62.

There is additionally provided a connecting rod 64, which has protrudingdownwardly from one end thereof a slide element 66, which fits closelybut slidably within a rectangular groove 68 which extends along thelength of the rocking box 60. The opposite end of the connecting rod 64is pivotally connected as at 70 to the outer extremity of an upper arm'72. The other end of the arm 72 is securely fastened to a verticalshaft '74 which in turn is mounted for pivotal movement in upper andlower bearings 76 and 78 on the housing 12. A lower arm 80 of arcuateconfiguration is fixedly attached to the lower end of the vertical shaft74 so that it will pivot along with the upper arm '72.

There is provided an interlocking shaft 82, one end of which is providedwith a lug 84 abutting the lower arm 80, and the other end of which ispivotally connected as at 86 to one end of an abutting rod 88. Theabutting rod 88 extends from the pivot point 86 out through a guideopening 90 in the housing 12 and abuts up against the needle bar support42. A return spring 92 is tensioned between the needle bar support 42and the housing; and serves to urge the needle bar support toward theright as viewed in FIG. 5. The force of the return spring 92 iscommunicated via the needle bar support 42 and the abutting rod 88,through the interlocking shaft 82 to urge the lug 84 against the lowerarm 80.

It will be appreciated that as the main shaft 36 rotates, this rotationis communicated via the zigzag worm 52 and the zigzag worm wheel 54through the lobe cam 53 to oscillate the rocking box 60 about its pivotpoint 62. This oscillatory movement is communicated through theconnecting rod 64, the upper and lower arms '72 and St) of the verticalshaft 74, the interlocking shaft 82, the abutting rod 88 and the needlebar support 42 to provide zigzag motion in the path of the arrowillustrated at S.

It will further be appreciated that while the lobe cam 53 is of a fixedsize, and thereby produces a fixed degree of oscillation to the rockingbox en, the amount of pivotal movement communicated to the verticalshaft 74 will vary as the distance between the slide element 66 and thepivotal connection 62 is changed. That is, as the slide element 66 ismoved outwardly toward the lobe cam 53, it will experience greateramplitudes of reciprocal motion and thus produce greater pivotalmovement of the vertical shaft '74 and consequently a larger swing tothe needle bar support 42. Conversely, as the slide element 66 is movedback toward the pivotal connection 62, the amplitude of needle bar swingwill be diminished.

There is additionally provided a pattern worm 94- also connected to turnwith the main shaft 36. The pattern worm 94 is meshed with a patternworm wheel 96 which turns a pattern cam 93. The pattern cam has aspecially configured outer periphery 100 which is engaged by a followerelement 102 located intermediate the ends of a follower arm 104. One endof the follower arm is pivoted as at 106 to the housing 12 of themachine, while its opposite end is pivotally connected via a link 108 toa point intermediate the ends of the connecting rod 64.

During operation of the machine, the needle bar 2% reciprocatesvertically and zigzags as above described. At the same time, the patterncam rotates and the follower element 102 moves in conjunction with thepattern defined by the peripheral surface of the cam. This movement inturn causes the follower arm M4 to swing about its pivot point 106; sothat its opposite end acts through the link 103 to adjust the positionof the connecting rod 64. This in turn changes the position of the slideelement 66 within the rectangular groove 68 of the rocking box 60; andaccordingly, as above described, will vary the amplitude of needle barswing.

In order to provide adjustment of needle swing amplitude or stitch widthaccording to the present invention there is provided an intermediateamplitude control lever 110 having a protruding arm 112 which extendsout from the side of the machine as illustrated in FIG. 1. Theintermediate amplitude control lever 110 is pivoted as at 114 within thehousing 12; and it includes an actuating arm 116 which engages theinterlocking shaft 82 by means of a pin and slot connection 118. Bymoving the intermediate amplitude control lever 110 and causing it topivot about the axis 114 the interlocking shaft 82 will be caused tomove about its pivot point 86 thus bringing the lug 84 into differentpositions along the arcuate face of the lower arm 80. The length of theinterlocking shaft 82 and the arrangement of the lower arm 80 are madesuch that when the rocking box 64) is at the center of its swing, thepivot point 36 will be at the center of curvature of the arcuate face ofthe lower arm 80. Thus the intermediate amplitude arm lever 110 may beshifted without causing any change in the position of the needle baryet, when the rocking box 60 begins to reciprocafe, its effect upon themovements of the needle bar 20 will be changed according to the positionof the intermediate amplitude control lever 110.

It will be noted that with the arrangement of the present invention, nochange need be effected either in the lobe cam 58 or in the pattern cam98; and yet, the amplitude of needle bar movement can be preciselycontrolled from outside of the machine.

The significance of the above described operation will be appreciated byreferring to FIGS. 2, 3 and 4 which show respectively a single needle24, two needles 24' and three needles 24 connected via a collar 22 tothe lower end of the needle bar 20. In FIG. 2, the collar 22 connectsthe single needle 24 to the needle bar 20 whereas in FIGS. 3 and 4,needle yokes 120 and 122 connect a pair of needles 24' and a trio ofneedles 24" respectively to the needle bar 20.

As illustrated in FIG. 2 when a single needle 24 is used on thismachine, the needle swing amplitude for any given pattern can extendover the full length of the needle opening 26 in the base plate 16. Thusfor the various sewing patterns illustrated at A, B and C to be madewith a single needle the needle swing can be adjusted to traverse theentire length of the needle opening 26. Where two needles are to beused, as for example, when embroidery stitching utilizing two differentcolored threads or when parallel patterns are to be producedsimultaneously, as illsutrated in FIG. 3, two needles 24' are used.However in using two needles, the pattern width must be reduced by onehalf so that the needles will not, in their extreme positions, impingeupon the base plate 16. Accordingly by adjustment of the intermediateamplitude control lever 110, the interlocking shaft 82 may be brought toa position closer to the axis of the vertical shaft 74 so that theeffect of the oscillatory movement of the rocking box so will not be asgreat upon the needle swing. Similarly, where, as illustrated in FIG. 4,three needles 24 are to be used, and the pattern should be one third thewidth of the pattern produced by a single needle as illustrated in FIG.2, the intermediate amplitude control lever is further adjusted to bringthe lug 84 of the interlocking shaft 82 even closer to the axis of thevertical shaft 74, thus reducing the needle swing even further.

In order to provide a convenient and accurate adjustment of needle swingamplitude, there may be provided on the outside of the housing 12 anindicator scale 124 showing the numbers 0, 1, 2 and 3 which show thatthe positions of the protruding arm 112 of the intermediate amplitudecontrol lever 110 when using the various numbers of needles duringsewing. Also, when it is desired to vary the amplitude of any givenpattern without changing the entire pattern cam, for example, when it isdesired to vary the width of a given butt-on hole stitch, the protrudingarm 112 of the intermediate amplitude control lever 110 may be adjustedgradually during sewing or it may be set at any given fixed position.

It will be appreciated that when the machine is set to produce nonzigzagor straight sewing and the lobe cam 58 is set to move the rocking box 60to a position where the lower arm 8t is such that its center ofcurvature is displaced from the pivot point 86 of the interlocking shaft82, the intermediate amplitude control lever 110 when pivoted will causean adjustment of the position of the needle bar support 42 so that theposition of the needle bar 20 may be conveniently adjusted.

Having thus described my invention with particular reference to thepreferred form thereof, it will be obvious to those skilled in the artto which the invention pertains, after understanding my invention, thatvarious changes and modifications may be made therein without departmentfrom the spirit and scope of my invention, as defined by the claimsappended thereto,

What is claimed as new and desired to be secured by Letters Patent is:

1. In a zigzag sewing machine having a push rod, a needle bar whichmoves sidewards in response to said push rod acting thereagainst, anadjustable swing amplitude control mechanism comprising a rocker barconnected at one end to pivot about a fixed point in said machine in aplane parallel to said push rod, a connecting arm also pivoted at oneend to a fixed point in said machine, a connecting link pivotallyconnected at one end to the other end of said connecting arm, the otherend of said connecting link being pivotally and slidably connected tosaid rocker bar at selectable points therealong to control the swingamplitude of said needle bar, an arcuate arm, means mounting saidarcuate arm parallel to and rotatable with said connecting arm, aninterlocking lever having means pivotally connecting one end thereof tosaid push rod and control means operatively connected to said lever tocause the other end of said interlocking lever to pivotally and slidablyinterconnect with said arcuate arm at selected points therealong.

2. Apparatus as in claim 1 wherein said needle bar is resiliently biasedagainst said push rod and said arcuate arm is provided with an arcuatesurface facing said push rod and said other end of said interconnectinglever is provided with a depending pin which engages said arcuate face.

3. Apparatus as in claim 2 wherein said interconnecting lever isprovided with a slot intermediate its ends and said control meansincludes a lever pivotally connected to said machine and having a pin atone end thereof which engages said slot.

4. In a zigzag sewing machine having a push rod, a needle bar whichmoves sidewards in response to said push rod acting thereagainst, anadjustable swing amplitude control mechanism comprising a rocker armconnected at one end to pivot about a fixed point in said machine, aconnecting arm also pivoted at one end to a fixed point in said machine,a connecting link pivotally connected at one end to the other end of oneof said arms, the other end of said connecting link being pivotally andslidably connected to the other of said arms at selectable pointstherealong to control the swing amplitude of said needle bar, an arcuatearm, means mounting said arcuate arm to rotate with said connecting arm,an interlocking lever having means pivotally connecting one end thereofto said push rod and control means operatively connected to said leverto cause the other end of said interlocking lever to pivotally andslidably connect with said arcuate arm at selected points therealong,

5. Apparatus as in claim 4 wherein said connecting arm and said arcuatearm are each aflixed at their respective pivoted ends to said mountingmeans, said mounting means comprising a rod mounted for rotatablemovement about a fixed axis in said machine.

References Cited by the Examiner UNITED STATES PATENTS 592,510 10/1897Parkes 112-158 3,217,677 11/1965 Eguchi l12158 JORDAN FRANKLIN, PrimaryExaminer.

RICHARD J. SCANLAN, I 11., Examiner.

1. IN A ZIGZAG SEWING MACHINE HAVING A PUSH ROD, A NEEDLE BAR WHICHMOVES SIDEWARDS IN RESPONSE TO SAID PUSH ROD ACTING THEREAGAINST, ANADJUSTABLE SWING AMPLITUDE CONTROL MECHANISM COMPRISING A ROCKER BARCONNECTED AT ONE END TO PIVOT ABOUT A FIXED POINT IN SAID MACHINE IN APLANE PARALLEL TO SAID PUSH ROD, A CONNECTING ARM ALSO PIVOTED AT ONEEND TO A FIXED POINT IN SAID MACHINE, A CONNECTING LINK PIVOTALLYCONNECTED AT ONE END TO THE OTHER END OF SAID CONNECTING ARM, THE OTHEREND OF SAID CONNECTING LINK BEING PIVOTALLY AND SLIDABLY CONNECTED TOSAID ROCKER BAR AT SELECTABLE POINTS THEREALONG TO CONTROL THE SWINGAMPLITUDE OF SAID NEEDLE BAR, AN ARCUATE ARM, MEANS MOUNTING SAIDARCUATE ARM PARALLEL TO AND ROTATABLE WITH SAID CONNECTING ARM, ANINTERLOCKING LEVER HAVING